I've heard of people getting water injected under their skin by an impeller engine, and I very nearly experienced this when I was thrown off the back of a jetski while a friend was doing a 360, and into the jet.

My friends who listen to what I build, then when they get confused I explain. Fun way huh? My favorite explanation, "Put it this way, its 20 pounds per square inch is like putting 20 pounds of make up on every square inch of your face" (my friend) "Ohhh that makes sense!" See how fun it is to explain to girls.